US lawmakers were locked in talks over what is likely to be the last spending deal of Barack Obama’s presidency at the weekend as Democrats seek to fund the White House’s final year agenda while Republicans try to undermine it.

Republicans seek to undercut Obama via spending bill

US lawmakers were locked in talks over what is likely to be the last spending deal of Barack Obama’s presidency at the weekend as Democrats seek to fund the White House’s final year agenda while Republicans try to undermine it.

With a Friday deadline looming for a deal on government spending priorities, congressional leaders were negotiating over policy changes that Republicans want to attach as the price of their support, aides said.

Democrats and the White House have vowed to oppose “poison pill” provisions that they say undermine the president’s legacy and bear no direct relation to the task of deciding how to dole out budget funds.

But Republicans hostile to Mr Obama want to take advantage of one of the last major pieces of “must pass” legislation before the 2016 presidential poll, knowing it would be politically difficult for the president to veto.

Stan Collender, a former congressional official now at Qorvis Communications, said: “It’s the last big bill that members may have before the election to get their pet projects funded or make a political statement with some of the policy riders.”

Just over a year from the end of a presidency scarred by budget brinkmanship, the White House and congressional leaders need to allocate $2tn approved in a surprise October budget deal that authorised discretionary spending for two years to September 2017.

If negotiators fail to agree on a so-called omnibus bill by Friday, when current federal spending runs out, the US would face the outside chance of a government shutdown. But both parties want to avoid one and would probably buy more time to seal a deal by authorising a short-term funding extension.

Mr Obama’s funding priorities include education, infrastructure, employment and job training programmes, as well as research and development.

“To get his priorities he’s going to have to give up on opposing some of these policy riders,” said Doug Holtz-Eakin, former head of the Congressional Budget Office and president of American Action Forum, a think-tank. “He’s not going to give up on all of them. But he’ll give up on some.”

A Democratic aide said the universe of potential riders was vast: “It really could be anything.”

Congressional insiders and people close to the White House said the following four issues were the most contentious.

Climate change

With ministers arriving in Paris on Sunday for the last five days oftalkson a global accord to limit greenhouse gas emissions, Republicans have launched an assault on Mr Obama’s effort to make action on climate change part of his legacy.

Friday’s spending deadline gives them a chance to hurt Mr Obama by inserting legislative language that stops him from giving $3bn he has pledged to a UN climate fund for developing countries.

Senate Republicans have called the vehicle a “slush fund for foreign bureaucrats”.

Refugees

The Paris terrorist attacks and last week’s mass shooting in California have sparked fresh alarm about border security, encouraging Republicans to put a spotlight on the perceived dangers of White House plans to admit 10,000 Syrian refugees to the US in the next 12 months.

Republicans are pushing riders that would block funding for the federal refugee resettlement programme, or suspend it until the authorities have verified that no refugees pose a threat to national security.

The issue is a priority for the conservative Freedom Caucus, a small but vocal group of House members who say current vetting is inadequate. The process takes 18 to 24 months and Democrats say there is no evidence that it is not working.

Financial reform

The Dodd-Frank reforms prompted by the last financial crisis are an enduring target for Republicans, who say they are strangling banks in red tape. The omnibus legislation provides a chance to water down some of its provisions, as occurred in a spending bill at the end of 2014.

High on the list of hoped-for changes are raising a $50bn asset threshold for banks designated as “systemically important”; diminishing the authority of the Consumer Financial Protection Bureau, a watchdog; and cutting off funding for a rule to raise conduct standards for pensions advice.

Jack Lew, Treasury secretary,warnedin a Bloomberg article last month: “Many of the changes masquerading as small or technical are significant, and they would weaken our financial system.”

Campaign finance

Watchdogs that monitor political spending say Republicans are trying to use the omnibus to deregulate campaign finance even further and clear the way for wealthy super-donors to exercise more influence.

Mitch McConnell, the GOP’s Senate majority leader, ispushingto eliminate caps on the sums political parties can spend in co-ordination with their candidates. Other potential riders would help donors to stay anonymous.

Fred Wertheimer of Democracy 21, which campaigns to curb big money in politics, said the goal was to keep “dark money” flowing. “That’s secret money and that’s the most dangerous money in politics [because] there’s no way to hold officeholders accountable if they start selling government decisions.